Outcome of repair of myocardial bridging at the time of septal myectomy

Background Myocardial bridging describes systolic compression of the muscular investment of a portion of an epicardial coronary artery. We evaluated the outcome of muscular bridge unroofing of the left anterior descending artery at the time of septal myectomy in patients with hypertrophic cardiomyopathy. Methods We conducted a case-controlled study of 36 patients (23 men; median age, 42 years) with hypertrophic cardiomyopathy and myocardial bridging. Group 1 patients had septal myectomy and concomitant unroofing (n = 13), group 2 patients underwent myectomy alone (n = 10), and group 3 patients were treated medically (n = 13). Results Angina was more prevalent preoperatively in group 1, 46% compared with 20% in group 2. Preoperative left ventricular outflow tract gradients of 67.8 ± 58.2 mm Hg and 74.1 ± 19.7 mm Hg were reduced to 1.9 ± 2.9 mm Hg in group 1 (p < 0.0001) and to 5.6 ± 8.8 mm Hg in group 2 (p < 0.0001). In the surgical groups, there were no early deaths or complications related to unroofing. Survival at 10 years was 83.3% in group 1 (p = 0.297), 100.0% in group 2, and 67.9% in group 3; there were no late sudden deaths. At follow-up, 77% in group 1 were asymptomatic compared with 70% of patients in group 2 (p = 0.19). There was no recurrent angina in group 1. Conclusions Myocardial unroofing can be performed safely at the time of septal myectomy for left ventricular outflow tract obstruction. Angina was improved, but we found no difference in late survival compared with patients who had myocardial bridging and myectomy alone. Unroofing should be considered in patients with angina who have significant left anterior descending artery bridging and require myectomy.